A novel double insertion of the difluoromethylene unit from trifluoromethylcopper into the carbon–copper bond of perfluoroaryl- and perfluorovinylcopper reagents: preparation, mechanism and applications of new fluorinated copper reagents
作者:Zhen-Yu Yang、Donald J. Burton
DOI:10.1016/s0022-1139(99)00247-x
日期:2000.3
(E)-CF3CFCFCF2CF2Cu, which could be trapped with allyl bromide to give (E)-CF3CFCFCF2CF2CH2CHCH2. When CF2CFCu was used as a substrate, (E)-CF3CFCFCF2CF2Cu was observed, but in low yield. A mechanism for this novel double CF2 insertion is proposed to involve a copper difluorocarbenoid complex intermediate, which inserted into the carbon–copper bond of the fluorinated phenyl and vinyl coppers to form fluorinated
CF 3 Cu与由CuBr和五氟苯基镉C 6 F 5 CdX制备的五氟苯基铜反应,得到双CF 2单元插入产物C 6 F 5 CF 2 CF 2 Cu,产率为70-80%。在室温下,在CuBr存在下,CF 3 MX(M = Cd,Zn; X = Br,CF 3)和C 6 F 5 CdX的插入反应也很好,得到C 6 F 5 CF 2 CF 2 Cu。使用乙烯基铜类似物(Z)-CF 3CFCFCu,双CF 2插入也发生导致的形成(ë)-CF 3 CFCFCF 2 CF 2铜,其可以与烯丙基溴被捕获,得到(É)-CF 3 CFCFCF 2 CF 2 CH 2 CHCH 2。当使用CF 2 = CFCu作为衬底时,观察到(E)-CF 3 CF =CFCF 2 CF 2 Cu,但是产率低。这种新型双CF 2的机理有人建议将其插入二氟卡宾铜络合物中间体中,然后将其插入氟化苯基和乙烯基铜的碳-铜键